Hello, suddenly about a month ago my thunderbird stopped showing attachments from senders that use apple mail. Is this a common problem and what can be done?I can now get the attachments that aplle mail users send from webmail only.

What version of Thunderbird? Check that under Help->Troubleshooting information.Any recent changes in your computer or software configuration that might be relevant?(including OS or Thunderbird updates, adding extensions or themes, etc. and any security program updates)If you view the message in Thunderbird and press Ctrl+U, there should be a block of text similar to this which references the name of the file attached to the message:

What do you mean by "stopped showing attachments"? They aren't listed as attachments at the bottom of the message? You're set to show attachments inline, but they don't display in the text box when viewing the message? Something else?

DanRaisch wrote:By definition a plain text message would display...plain text. Attachments would appear as attachments, not as images within the message.

I am well aware that a plain text message displays "...plain text". However, any attachments; embedded in the message or separate attachments are displayed at the bottom of an email.

Lately, and it does seem to be related to Apple mail, any sort of attachments are not displayed at the bottom. As the OP said when message body is viewed in any version of html not only do in line attachments show up but separate ones display at the bottom.

I thought this was a support forum? It is not like people are all upset because our daisy-wheel printer doesn't print the font we see on the screen. It is typically more secure to view email as plain text to reveal the true url in links, etc. The attachments have always been in the bottom of the viewing pane on plain text emails and now they aren't. All you are doing is asking us why we are wanting to view emails plain text and not giving us vectors for reporting this properly upstream.

Please use Control-U to look at the raw source of a small message from a Apple email client that causes a problem, and copy and paste the entire message into a private message (see the PM icon to the left of my post) that you send to me. If you want to hide any email addresses please just replace ONLY the username portion with something obviously generic but unique like username_1 , username_2 etc.

It might be easiest to copy and paste the raw message source into a text editor (NOT a word processor), use a global search/replace to hide the usernames and then copy the modified text into the private message. I'll merge that message into a mbox file on my system and try to duplicate the problem.

Or copy it into something like dropbox and post a link. Please note that I'm asking for the raw message source as displayed by Thunderbird - not a copy of a message that you saved to a .eml file, or an excerpt from a mbox file.

Does using something like https://addons.mozilla.org/en-US/thunde ... ts/?src=ss have any effect? I'm wondering if Thunderbird is trying to display the attachment inline (as part of the message, rather than as a separate attachment that you have to open) and its getting hidden for some reason. Some newsletters for example have so many MIME parts, many of them nested, that Thunderbird can get real confused trying to parse the layout of the message.

Thank you so much for replying with steps to actually look at the issue. The users and community appreciate it.

The use case is viewing all messages in plain text. Most other clients, when sending attachments, just have it at the bottom of the message in the attachments bar. Lately it seems that apple mail clients only (that I can see) seem to not show the attachments while viewing messages in plain text. They do become available when using simple or regular HTML. However, there are security reasons many people view messages as plain text (the article I posted earlier). This is new behavior. Other emails from apple mail did not behave this way.

I did just now try the addon you suggested and it does work, but it is showing everything: plain, html, and attachments. While this can be a work around, if the old behavior was to show the attachments at the attachments bar and only Apple mail is impacted; that is the issue.

Thanks again!

tanstaafl wrote:Does this problem occur for both text and binary attachments?

Does using something like https://addons.mozilla.org/en-US/thunde ... ts/?src=ss have any effect? I'm wondering if Thunderbird is trying to display the attachment inline (as part of the message, rather than as a separate attachment that you have to open) and its getting hidden for some reason. Some newsletters for example have so many MIME parts, many of them nested, that Thunderbird can get real confused trying to parse the layout of the message.

I imported the message you gave me into a Gmail IMAP account. I had to install a compatibility pack for Office 2007 to read the .docx file attachment but once I did, I had no problem reading the "Study Guide Week 16.docx" attachment. The message also had a 5and6_1718 mailing list inline attachment (a mailing list signature, not the authors signature). I tested it using 52.6.0 , 58.0b2 (beta) and 60.0a1 (daily build) under Windows 10. No problems in each case. I also retested 52.6.0 in safe mode to verify that an add-on wasn't the reason why I could see the attachment icon.

The attachment had a Content-Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document; x-unix-mode=0644; header rather than a more typical Content-Type: application/msword. I'd normally expect that to cause a problem figuring out what utility to open the attachment with, not a problem seeing that there is an attachment.

UEsDBBQABgAIAAAAIQDKPj/bcQEAANkFAAATAAgCW0NvbnRlbnRfVHlwZXNdLnhtbCCiBAIooAACAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA... and so on. The last part is the actual file contents, base64 encoded in order to store it in a email message.

I'm using view -> message body as -> Original HTML. If I change it to "plain text" the attachment disappears. I still see the mailing list signature (inline attachment). The problem seems to be that the sender used multipart/alternative to describe how the different parts of the message should be organized/interpreted. That is a way of saying there are multiple versions of a MIME body part and which one is used depends upon your setting (view -> message body as).

In the simplest case you would see that where there is a message with just a plain text version of a message body and a HTML version of a message body. Only one version of the message body will be displayed. The email client is supposed to figure out which version to display based on user settings. In this case/message its a little more complicated, but its the same basic problem.

The message has a plain text version which has text, but no attachment. The HTML version has HTML encoded text plus the attachment. i.e. the senders email client should have put the attachment AFTER the multipart/alternative MIME body part ended, like it did for the inline attachment (list manager signature), so that it was always visible. As far as I can tell Thunderbird is not to blame. The problem is the .docx attachment was "bound" to the HTML version of the message body, when it should have been been made visible regardless of how you viewed the message.

I found a X-Mailman-Version: 2.1.23 header which means they used the GNU mailmen list manager but no User-Agent: header identifying the email client. Some of the boundary strings included "Apple-Mail" as substring, which I assume means some version of Apple Mail was used as the email client.

I copied the message from the Gmail IMAP account to a Outlook, Fastmail.fm, Yahoo, Vivaldi, Zoho and Comcast IMAP account, plus "Local Folders" (acts like a POP account). The Outlook account always displays the attachment, regardless of the view -> message body as setting. It never displays the list manager signature (regardless of Original HTML or plain text). I used view -> message source to verify the list manager signature really was omitted from the message! The multipart/alternative (and the corresponding plain text version) was also omitted. I don't know why it does this, but that explains why the attachment is always displayed. It basically edited the message to just have a HTML version of the message body (which has the attachment). Since there is only one version of the message body its always displayed, regardless of the view -> message body as setting.

The rest of the accounts display the attachment when using "original HTML", and don't display the attachment when using "plain text".